An old power supply design for the EZ80
A great little tool for checking your signal out
by: Tom Buchanan VE6ARG
It's just so easy to get into ham radio these days. You pass your Basic and then simply go on-line or walk into a store and buy everything you think you need and voila, you're on the air. But what was it like when there wasn't anything to buy and in most cases what was available was old military or commercial equipment that needed to be rubbered into working on the amateur bands? Well, a lot of us built our own. It wasn't uncommon to hear people on the air touting their homebrew equipment in those days. It was exciting and fun to put your own creations on the air. All you needed was an old ARRL Handbook, a bunch of surplus parts from the surplus outlets and some enthusiasm. Oh it also helped if you had a soldering iron and some other tools that could manipulate and put holes in metal. Armed with some Greenlee punches and some files and stuff, you were away to the races. My first transmitter was a 6L6, crystal controlled, cathode keyed oscillator with a pi network connected to a long wire from my bedroom window. It chirped like hell, but I made contacts with a modified Rogers Majestic receiver with an off-board BFO of my own design. My first contact was with a fellow named Brian VE7BPY I think his call was. He was on the other side of town. I was VE7ARG in those days.
Unfortunately someone decided to create equipment for hams that took that excitement away and made a whole bunch of appliance operators out of us. First there were kits made by Knight Kit, Heathkit and others that kept the irons hot for awhile, but that went away too after a few decades. The bloom went off the rose I guess when you could buy a great new rice box radio that did everything you could imagine and some. And the final blow was the authorities taking the ability of being able to build your own transmitter away from new hams with only the basic license. How sad.
I have been home brewing my own equipment for amateur radio ever since I was a kid and the techniques that I’ve developed and stolen from others have served me well. There is nothing quite so satisfying as making something work that you have built using your own hands and sometimes the simpler the project, the more satisfying. Anything from a simple scope sampler to show you how well your rig is modulating on an oscilloscope to a full, all band transceiver that you can use to listen and work the world is possible using these techniques.
The other day I came across a book by Frank Harris, W0IYE. Frank has obviously figured it all out and his ideas are contained within his wonderful book “Crystal Sets to Sideband”. It’s available on the internet. http://www.qrparci.org/wa0itp/csts_book.pdf and is a good read. He's very inspiring.
Back in the early 80’s there was an offshoot from the SAARC that we called the “Build it Club” and we met for a couple of years on Wednesday nights in my basement. There were about six of us as I remember and each person had a project that they wanted to build in various degrees of complexity. I was into small computer systems in those days and built an “EZ 80” computer that worked very well. We had the design for the circuit board and all the parts needed and it was satisfying to create the circuit board by photographic methods and etch it and plug it to make the finished product. Another person wanted to make an LED, 24 hour clock with the LED’s around the outside so that they would light up where the hands would be pointing in a regular clock.
All of this great experience moved my own career in process control along to the point that I became a promotional demo engineer working for a company in Vancouver. My job was to fashion demo equipment that used the products that we manufactured for the Allen Bradley company. I built dozens of items for them from a sophisticated linear positioner that punched a touchscreen computer with a boxing glove at a process control tradeshow to several years of award winning automated Christmas trees controlled by a touch screen. It was a great hit that the public could use to start and stop different light displays and an electric train running around the bottom of the tree. Many of these creations were built in my basement in Burnaby as well as prototypes of new products for proof of concept. What fun it all was.
If you are interested in creating your own equipment, let me know and we will see if we can get something going. Tell me about your projects both that you have done and ones you would like to create. Perhaps we can bring the fun and excitement of homebrewing back to amateur radio other than antennas. You can contact me at firstname.lastname@example.org or by phone at 403 634 8801.